Perl函数传引用(Scalar, Array and Hash)

#!/usr/bin/perl -w

use strict;
use warnings;
&main;
sub main {
my @array = (0, 1, 2);
my %hash = (
   '0' => 'a',
   '1' => 'b',
   '2' => 'c'
);
my $scalar = "call by value\n";
refFunction(\%hash, \@array, \$scalar);
print $scalar;
}

sub refFunction {
my($hash, $array, $scalar) = @_;

print "array \n";
foreach(@$array) {
   print $_ . "\n";
}
print "hash \n";
foreach my $key(sort keys %$hash) {
      print "$key->$hash->{$key}\n";
}
$$scalar = "call by reference";
}